1. Field of the Invention
The present invention relates to a heat exchanger incorporating therein a heat pipe apparatus which comprises an evaporator section and a condenser section separated from the evaporator section.
2. Description of the Prior Art
Various types of heat exchanger have been used so as to heat two or more fluids to be heated (lower temperature fluid) by means of one heating fluid (higher temperature fluid). A conventional heat exchanger, for example a heat storage rotary type heat exchanger, a multi-tubular pipe type heat exchanger or plate type heat exchanger among such heat exchangers each necessitates a division of a heating fluid flow into branch flows corresponding to the number of the fluids to be heated, whereby a heat exchange is effected between the branched heating fluid flow and the corresponding fluid to be heated, or necessitates a provision of the heat exchangers within the heating fluid each of which heats the corresponding fluid to be heated.
Under the above-mentioned circumstances, a heat exchanger has been proposed, which incorporates a heat pipe apparatus including an evaporator pipe section disposed within the flow of a heating fluid, condenser pipe section disposed within the flow of a fluid to be heated and located in series and spaced away from the evaporator pipe section, and passage means for connecting both pipe sections to each other. Generally, in this type of heat pipe apparatus which is so called the separate type heat pipe apparatus, it is necessary to provide therein sets of relief valve and non-condensable gas separator. However, as the number of the condenser pipe sections increases, the number of the sets of relief valve and non-condensable gas separator proportionally increases, too. Thus, the number of necessary parts and the cost for the heat exchanger increase.
Further, in the above-mentioned construction wherein both pipe sections are arranged in series, a difference between temperatures of the heating fluid and the heated fluid passing from through the condenser pipe section becomes smaller, so that it is required to increase the quantity of heat being exchanged at the upstream side of the fluid.